Genetically-engineered mice (transgenics, knockout and knock-ins) have become invaluable to almost all fields of medicine. Because of the importance of GEM to understanding human development and diseases and to creating improved drugs and therapeutics, tens of thousands of GEM have been created over the last decade. The MMRRC provides a unique repository service to the biomedical community for importing, storing and distributing a vast number of GEM as a resource for the biomedical community. Since the MMRRC Network began as a fledging repository in 1999/2000, it has evolved into a major resource for the biomedical community with capabilities and a combined inventory of mouse lines and embryonic stem (ES) cells that exceeds the capacity of other mouse repositories worldwide. The overall goal of this proposal is to continue and expand these functions and capabilities of the Mutant Mouse Regional Resource Center (MMRRC) at the University of Missouri to provide biomedical investigators with the mouse models and related reagents they require for their research.